Editing Foot (section)

=====''Posterior group''=====
The ''superficial layer'' of posterior leg muscles is formed by the [[triceps surae muscle|triceps surae]] and the [[plantaris muscle|plantaris]]. The triceps surae consists of the [[soleus muscle|soleus]] and the two heads of the [[gastrocnemius muscle|gastrocnemius]]. The heads of gastrocnemius arise on the [[femur]], proximal to the condyles, and the soleus arises on the proximal dorsal parts of the tibia and fibula. The tendons of these muscles merge to be inserted onto the calcaneus as the [[Achilles tendon]]. The plantaris originates on the femur proximal to the lateral head of the gastrocnemius and its long tendon is embedded medially into the Achilles tendon. The triceps surae is the primary plantar flexor. Its strength becomes most obvious during ballet dancing. It is fully activated only with the knee extended, because the gastrocnemius is shortened during flexion of the knee. During walking it not only lifts the heel, but also flexes the knee, assisted by the plantaris.<ref name="Platzer-262">Platzer 2004, p. 262</ref>

In the ''deep layer'' of posterior muscles, the [[tibialis posterior muscle|tibialis posterior]] arises proximally on the back of the [[interosseous membrane of leg|interosseous membrane]] and adjoining bones, and divides into two parts in the [[Sole (foot)|sole of the foot]] to attach to the tarsus. In the non-weight-bearing leg, it produces plantar flexion and supination, and, in the weight-bearing leg, it proximates the heel to the calf. The [[flexor hallucis longus muscle|flexor hallucis longus]] arises on the back of the fibula on the lateral side, and its relatively thick muscle belly extends distally down to the [[flexor retinaculum of foot|flexor retinaculum]] where it passes over to the medial side to stretch across the sole to the distal phalanx of the first digit. The [[popliteus muscle|popliteus]] is also part of this group, but, with its oblique course across the back of the knee, does not act on the foot.<ref name="Platzer-264">Platzer 2004, p. 264</ref>